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Zhao Z.-W.,Chinese Research Institute of Radio wave Propagation | Wang N.,Chinese Research Institute of Radio wave Propagation
Dianbo Kexue Xuebao/Chinese Journal of Radio Science | Year: 2010

By analyzing the variation of brightness temperature induced by water vapor and dry air due to change of temperature for the ground-based dual-channel radiometer operating at 23.8 GHz and 31.65 GHz, it is indicated that variation of brightness temperature induced by dry air can be ignored. The method to retrieve dry and wet refractivity profiles respectively is proposed, and the radial basis function method (RBF network) is first applied to retrieve refractivity profile. Based on historical radiosonde data, the dry refractivity profiles retrieved with linear and nonlinear regress method are compared with Hopfield model and radiosonde data, and the wet refractivity profiles retrieved by radiometer with linear regress, nonlinear regress, BP network and RBF network method are compared with radiosonde data. The results show that the dry and wet refractivity profiles retrieved by linear regress and the RBF network method have respectively better accuracy than other methods. ©2010 by Editorial Department of Chinese Journal of Radio Science. Source


Zhang S.,Chinese Research Institute of Radio wave Propagation | Han X.,Chinese Research Institute of Radio wave Propagation
Dianbo Kexue Xuebao/Chinese Journal of Radio Science | Year: 2015

Based on the wave-guide theory, the formulas used to calculate radiation fields excited by the airborne trailing antenna are deduced. According to the formulas, altitude gains are obtained, and the altitude gain fluctuation with the height of observing points is analyzed. Then, for the radiation fields excited by the trailing antenna, its variation characteristics with the antenna height, tilt angel and receiving azimuth angel are discussed, which has great reference value for trailing antenna study and application. ©, 2015, Chinese Research Institute of Radiowave Propagation. All right reserved. Source


Wang Y.-X.,Shanghai JiaoTong University | Wang Y.-X.,Chinese Research Institute of Radio wave Propagation | Pan W.-Y.,Chinese Research Institute of Radio wave Propagation | Jin R.-H.,Shanghai JiaoTong University | Zhang S.-T.,Chinese Research Institute of Radio wave Propagation
2010 9th International Symposium on Antennas Propagation and EM Theory, ISAPE 2010 | Year: 2010

It is the first time that the Antarctic super low frequency (SLF) and extremely low frequency (ELF) radio atmospheric noise has been measured in China. The time domain profile and the frequency domain profile of the data have been gained by analyzing and processing the measured data, and the change characteristic of the radio atmospheric noise has been discussed along the day, night and the frequency. The analysis of the measured data shows that the value of the radio atmospheric noise is very low in South Pole. It can reveal the real radio atmospheric noise because it avoids effectively the industry and the artificial electromagnetic interference. Moreover, the characteristic of Schumann resonance is very obvious. ©2010 IEEE. Source


Shu T.-T.,Xidian University | Han H.-M.,Xidian University | Guo L.-X.,Xidian University | Lin L.-K.,Chinese Research Institute of Radio wave Propagation | And 2 more authors.
2012 10th International Symposium on Antennas, Propagation and EM Theory, ISAPE 2012 | Year: 2012

The weighting functions are the foundation for understanding the reversion of the atmospheric profiles by ground-based radiometer. This article has analyzed the principle and the feature of microwave sensing of the atmospheric temperature profiles. The temperature weighting functions are calculated and analyzed by the atmospheric radiation transfer equation and atmospheric profiles obtained by radiosonde. The results can be used for the selection of the working frequencies of ground-based radiometer in atmospheric remote sensing. © 2012 IEEE. Source

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